Problem with enum and struct

[Paolo]

Hi all!
As I said in the title, I have a very strange problem compiling a
program Here's the code that gives the problem:

enum letters
{
a = 0,
b,
c
};

typedef struct
{
letters let;
int number;
} someStruct;

It gives me an error before letters in the struct. Any idea on
what generates this error? I have to say that this was a C++ code, but
it doesn't use any class or anything else incompatible with C, at least
I think so.
Thanks for the help!

[Vladimir S. Oka]

Re: Problem with enum and struct


Paolo wrote:[color=blue]
> Hi all!
> As I said in the title, I have a very strange problem compiling a
> program Here's the code that gives the problem:
>
> enum letters
> {
> a = 0,
> b,
> c
> };
>
> typedef struct
> {
> letters let;
> int number;
> } someStruct;
>
> It gives me an error before letters in the struct. Any idea on
> what generates this error? I have to say that this was a C++ code, but
> it doesn't use any class or anything else incompatible with C, at least
> I think so.[/color]

I don't know about C++ (ask in comp.lang.c++), but in C an `enum` does
not define a type, so you'd need:

enum letters let;

in your structure.

--
BR, Vladimir

[Carl R. Davies]

Re: Problem with enum and struct

Paolo wrote:[color=blue]
> enum letters
> {
> a = 0,
> b,
> c
> };
>
> typedef struct
> {
> letters let;
> int number;
> } someStruct;[/color]

typedef struct
{
enum letters let;
int number;
} someStruct;

or you could declare another typedef:

typedef enum letters letters_e;

then:

typedef struct
{
letters_e let;
int number;
} someStruct;

[Paolo]

Re: Problem with enum and struct

Thank you, I think I resolved. Another question, if I have a method
that returns an enum value, for example

letters GetFirstLetter( char* words);

do I have to add enum before letters?

[Carl R. Davies]

Re: Problem with enum and struct

Paolo wrote:[color=blue]
> Thank you, I think I resolved. Another question, if I have a method
> that returns an enum value, for example
>
> letters GetFirstLetter( char* words);
>
> do I have to add enum before letters?[/color]

IMHO yes. The word 'letters' alone doesn't denote a type, it must be
'enum letters' for it to be recognised as such. I always prefer
typedef(ing) enums and appending '_e', like 'letters_e'.

[Fred Kleinschmidt]

Re: Problem with enum and struct


"Paolo" <paomic@gmail.c om> wrote in message
news:1141310386 .740513.216130@ u72g2000cwu.goo glegroups.com.. .[color=blue]
> Hi all!
> As I said in the title, I have a very strange problem compiling a
> program Here's the code that gives the problem:
>
> enum letters
> {
> a = 0,
> b,
> c
> };
>[/color]

If you want to use "letters" as a type name, as you do in someStruct below,
you have to typedef it.
typedef enum {
a=0,
b,
c
} letters;
[color=blue]
> typedef struct
> {
> letters let;
> int number;
> } someStruct;
>
> It gives me an error before letters in the struct. Any idea on
> what generates this error? I have to say that this was a C++ code, but
> it doesn't use any class or anything else incompatible with C, at least
> I think so.
> Thanks for the help!
>[/color]
--
Fred L. Kleinschmidt
Boeing Associate Technical Fellow
Technical Architect, Software Reuse Project

[Micah Cowan]

Re: Problem with enum and struct

"Paolo" <paomic@gmail.c om> writes:
[color=blue]
> Thank you, I think I resolved. Another question, if I have a method
> that returns an enum value, for example
>
> letters GetFirstLetter( char* words);
>
> do I have to add enum before letters?[/color]

Yes, in C.

In your orinal post, you claimed that the code was C++ (which is
off-topic here, since /this/ group discusses only C). If that were
true, your code should have compiled (as would the above). It seems
very likely that you were compiling your "C++" code as C code, which
is why our solution worked. If it's really C++ code, make sure you're
compiling it with a C++ compiler. For implementations playing multiple
roles, this probably means you need to make sure your file ends in
..cc, .cx, or .C, rather than .c.

A lot of what I've just said is not really related to what we discuss
here on this newsgroup. If you would like your code to be C++ code,
and want to ask further questions about C++ code, ask
comp.lang.c++. If you want to ask how to get your compiler to compile
the code as C++ code, ask on a group related to your compiler.

HTH
Micah

[Keith Thompson]

Re: Problem with enum and struct

"Vladimir S. Oka" <novine@btopenw orld.com> writes:[color=blue]
> Paolo wrote:[color=green]
>> Hi all!
>> As I said in the title, I have a very strange problem compiling a
>> program Here's the code that gives the problem:
>>
>> enum letters
>> {
>> a = 0,
>> b,
>> c
>> };[/color][/color]
[...][color=blue]
>
> I don't know about C++ (ask in comp.lang.c++), but in C an `enum` does
> not define a type, so you'd need:
>
> enum letters let;
>
> in your structure.[/color]

Yes, an enum does define a type. The name of the type is
"enum letters", not "letters".

<OT>In C++, the type can be referred to as just "letters"; likewise
for classes, unions, and structs. This is one of the differences
between C and C++.</OT>

--
Keith Thompson (The_Other_Keit h) kst-u@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.